It is not enough these days to have a large, star-studded cast working in a movie that is terribly written. Such is the case with “The Big Wedding,” which turns out to be one big dud. The writers couldn’t make up their minds whether to make a comedy or tragedy, so we end up with one stupid soap opera.

Robert DiNiro plays the father of the groom, his adopted son (Ben Barnes). Alejandro’s biological mother is coming to the wedding, but she can’t speak English and she thinks DiNiro’s character is still married to Diane Keaton’s character. But he has taken up with Susan Sarandon’s character.

All the kids gather with their own problems to further muddy the water, while mom and dad pretend to still be together. It all gets very confusing without being funny or even carrying a message.

Robin Williams has a supporting role as the priest, but the director doesn’t allow him any freedom to be himself in a wasted role.

I won’t waste your time. This is a terrible movie. I went online after I saw it to Google Rotten Tomatoes to see if I had missed something. It had a critic’s rating of 7, the lowest I’ve ever seen.